1. Field of the Invention
This invention relates to a process for producing a halogenated aromatic amine compound.
2. Related Background Art
Halogenated aromatic amine compounds are useful compounds as intermediates of pharmaceuticals and agricultural chemicals, intermediates of coloring matters such as organic dyes and pigments, and also intermediates of organoelectroluminescence materials, and intermediates of photosensitive materials or organic conductor materials of organic photosensitive members in electrophotography.
In synthesizing halogenated aromatic amine compounds by conventional processes, they have been synthesized by, e.g., in the case of aminobiphenyl compounds, the reaction in which an aminobiphenyl compound is directly halogenated, or the Ullmann reaction in which a dihalogenated biphenyl compound and an amine compound are heated at a high temperature in the presence of a copper reagent (DAIYUHKI KAGAKU (Grand Organic Chemistry), Vol. 16, 52(1959), Asakura Shoten; YUHKIKAGAKU KOZA (Organic-Chemistry Course) 3, 66 (1983). However, in the reaction in which an aminobiphenyl compound is directly halogenated, an isomer different in halogen substitution position is present, and hence the desired compound can not efficiently be obtained. In the Ullmann reaction as well, the reaction has no selectivity, and hence not only the desired halogenated aminobiphenyl compound but also a diaminobiphenyl compound are simultaneously formed to make it unable to obtain the desired compound efficiently. Accordingly, it has been sought to provide a process for producing halogenated aromatic amine compounds efficiently.
Recently, a method developed by Buchwald or Hartwig et al. is also reported in which an arylhalide compound and an amine compound are allowed to react in the presence of a palladium catalyst to synthesize an arylamine compound efficiently (Tetrahedron Letters, Vol.36, No.21, p.3609, 1995; J. Am. Chem. Soc., V61.120, p.9772, 1998; J. Or. Chem., 61, p.1133, 1996). Syntheses in which this reaction is applied to the syntheses of dihalogenated biphenyl compounds are disclosed in Japanese Patent Applications Laid-open No. 11-21349 and No. 11-322679. In either of them, however, all halogen moieties of a dihalogenated biphenyl compound are aminated, and there is shown no example of synthesizing halogenated aminobiphenyl compounds.